Trim Tabs - options - wake surfing (and cruising)

[jcyamaharider]

Are you not able to control the tabs individually? Most controllers allow that.

His were only auto.....I think????

 

[Glen]

@swatski, I am SSSOOO with you!
Makes perfect sense to me to spend $1000's to get powered tabs that both help with nose rise in rough waters, as well as help shape the wave for surfing when in ballast mode. Like so many things in life, I would sacrifice some performance, for the convenience!
If there is East Coast engineering necessary to get this right, I'll bring my boat where ever necessary.
Giddy up!!

 

[swatski]

@swatski, I am SSSOOO with you!
Makes perfect sense to me to spend $1000's to get powered tabs that both help with nose rise in rough waters, as well as help shape the wave for surfing when in ballast mode. Like so many things in life, I would sacrifice some performance, for the convenience!
If there is East Coast engineering necessary to get this right, I'll bring my boat where ever necessary.
Giddy up!!

I'm hoping the Lectrotab deal that @Bruce finagled in 2014, linked up here, will work! The Lectrotab guys are an engineering company and those tabs are a real deal. They have been primarily an OEM supplier and have not built huge marketing, but their design seems superior. For example, those are the only electric tabs with very clever pressure relieve valves built in (to prevent vacuum built up inside the actuators during operation), etc. I'll post when I hear back from them.

I think it should be possible to configure Lectrotabs to loose NO speed or performance in lake driving in flat water, if anyone is worried about it.

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[OperationROL]

The link below shows what I had on my former 230. The tabs are great for "anti-porpoising" and evening out the boat under unbalanced load but had a negative effect on the wake, even when they where at point zero and not deployed.

https://jetboaters.net/threads/trim-tabs-on-2015-242-ls.6603/#post-113345

 

[Mainah]

Check out the last photo in the quoted post below (I also copied and inserted). Gives a great picture of what things look like while underway. I think a trim nozzle like there use to be on some jet skis would be great idea to try for surfing, wakeboarding, and rough seas/lake. A higher top end speed may even be possible with very slight trim. Of course this would require additional cables/levers or electro mechanical controls but instead of bouncing the water jets off a plate why not just redirect from the source which would be more efficient. Someone on here must have the machining chops to replace the direction control and reverse bucket with a traditional trim/steering nozzle and even improve the reverse bucket design while at it.

Some pictures of the boat at Bear Lake this past weekend. The water their is pretty awesome!

View attachment 27500 View attachment 27501 View attachment 27502 View attachment 27503 View attachment 27504 View attachment 27505 View attachment 27506

 

[Mainah]

Come to think of it perhaps all someone needs to do to test this out would be find some small used Berkeley jetovators or similar and have some adaptor plates made up along with shoehorning some extensions for the existing steering and bucket control cables and a temporary trim controls.

 

[swatski]

Check out the last photo in the quoted post below (I also copied and inserted). Gives a great picture of what things look like while underway. I think a trim nozzle like there use to be on some jet skis would be great idea to try for surfing, wakeboarding, and rough seas/lake. A higher top end speed may even be possible with very slight trim. Of course this would require additional cables/levers or electro mechanical controls but instead of bouncing the water jets off a plate why not just redirect from the source which would be more efficient. Someone on here must have the machining chops to replace the direction control and reverse bucket with a traditional trim/steering nozzle and even improve the reverse bucket design while at it.

View attachment 49285

Yes, I agree, something like Place Diverter w/controls could be very useful, especially if it could operate independently on both nozzles. BUT -- that is not happening anytime soon. It would be a major redesign project. Well beyond the scope of what I would be willing to tackle right now for example.
That said, I may try to tackle it in a different way:
https://jetboaters.net/threads/asp-aerial-surf-platform-like-device-for-yamaha.12015/page-2

@OperationROL I think you are exactly right, and it is going to be the most difficult issue -- to get the range of the tabs such that they would retract enough as not to interfere on the surf side. Wake boats' surf tabs, such as in the pics I posted earlier in this tread, tend to retract a lot more than the traditional "cruising" tabs and some are mounted further up on the transom. But then -- they also have strait transoms to work with. AND - most of them do not drive their boats across the Gulf Stream, LOL.

Thank you for posting guys!

We also just got an email response from Dan of Lectrotab, who is incredibly responsive, so we may have them on our side! More to come, for sure.

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[jcyamaharider]

The above picture is only for on plane watersports, wake boarding, skiing, tubing...etc. While Wake surfing ( not on plane ) it is a different animal. The jets are still under water

 

[swatski]

The above picture is only for on plane watersports, wake boarding, skiing, tubing...etc. While Wake surfing ( not on plane ) it is a different animal. The jets are still under water

Of course. But I am not surprised with what @OperationROL said, needs to be considered (I'm assuming he is referring to wake surfing not wake boarding):

The tabs are great for "anti-porpoising" and evening out the boat under unbalanced load but had a negative effect on the wake, even when they where at point zero and not deployed.

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[swatski]

So... after some 20+ cutouts of various tab-actuator combos, I think I'm starting to get a grip on what needs to be done! Needless to say, it will be a compromise, but a good one (I hope).

The goal is, as stated, to design and fabricate trim tabs that would aid both cruising attitude (as traditional tabs would) but also help with wake surfing (which is what "wake plates" are called for).

So, what's the difference?

TRIM TABS vs WAKE PLATES
Trim tabs and wake plates are essentially the same thing: metal plates attached to the rear of the boat using a hinge and a hydraulic or electromechanical (the latter being our choice here) shock. Honestly? -- I think the main difference is regular boats call them "trim tabs" and wake boats call them by many other names to make them sound cooler...
Check this out:
Attitude Adjustment Plate (MC), Taps (Tige), SmartPlate (SC), Quick Plane Cavitation Plate (MB), Hydro-Gate (CC), etc, even MC's surf tabs are basically trim tabs... Basically, Centurion, Sanger, WB, Supra, MC, Supreme, Tige, etc are using a Bennett/Lenco trim tab and calling it a wake plate. Or in other words, same parts with a different use.
(all of that is MHO only, of course)

That said, there is ONE THING that really stands out for me (other than wake plates can have funny shapes): the angle in fully retracted position.

Traditional trim tab with a typical 12" chord (fore-aft length) is mounted flash or 1/4" above the bottom of the hull with the plane set so it is at less than an inch (typically 5/8") up at the trailing edge or just a couple deg up off of the hull's plane (when fully retracted). In contrast, wake plates are generally retracted up at a much more aggressive angle, as much as 10-15deg (again, when fully retracted). Here, the deployed tab goes on the opposite side of where you will be surfing, while the retracted one on the surf side does not interfere with creation of a large wave with tons of push. The latter being the key point, the way I see it.
For example:

Standard tab mount VS Wake plate tab (many are even more aggressive, or "up")



With Yamaha transoms, we are SEVERELY vertically challenged -- one major obstacle to mounting a true wide range tabs/plates. Of course, anything can be done. But short of designing recessed actuators etc. (I'm NOT interested in anything of that nature) it is just not quite doable as a simple bolt-on mod.
Incidentally, all of the Yamaha tabs' installations I know of are (more or less) flush with the hull when retracted, as below:

@1948Isaac @OperationROL


@Bruce @Glassman


@paul075 (and there is another, TBA - I know I'm missing someone... please help!)


FOUND IT! @bucks448


So, there is no perfect solution... BUT
I think there is a good compromise that can be achieved, a simple approach using a balanced tab/wake plate -- actuator combo. That could even serve as a simple hull extension device to lengthen the hull by as much as the chord length to create a larger wave with tons of push.

(More below - in the next post)

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[swatski]

We are working off of the Lectrotab design of @Bruce and Dan Roberts of Linear Devices Corp (parent company making Lectrotabs). The standard tab dimensions in that kit are 12"x12" (chord x span), 14" actuator, and the attachment point is at 7.75" from the hinge/hull.

Those work really well for boat attitude adjustments, or as regular trim tabs. However, there are several issues with the above tabs/actuators if used as wake tabs, the way I see it. Most notably, those overall dimensions would NOT be compatible and potentially interfere with other wake shaping devices. For example, Gantlin Wake Wedge install would NOT be possible. Or other devices, such as an adjustable ASP-like platform (AKA Swatski's Tail, LOL), etc.

Shortening the actuators, the ONLY readily available solution, would dramatically reduce the tabs' range of motion due to the reduced stroke of the "short" actuator, 2.25" standard vs 1.5" "short". The only way to compensate for that is to move the attachment point closer to the hinge/hull, which would also weaken the load rating, which needs to be compensated for with the shorter chord (but longer span to retain the surface..). Etc, etc.

So, long and short, here are some considerations and solutions we came up with.

SPAN
The general recommendation is using tabs that are 9 inches in chord (distance from transom to trailing edge of the tab) the tabs should be one inch in span (width port to starboard) for each foot of boat. Accordingly, tabs for my boat should be 24" x 9".
The largest span of the tab that can be easily fitted is 16" (again, that is the width, or port to stbd measurement).
Making the tabs 16" x 9" would do the trick, close enough to 216 square inches to make a noticeable difference in lift without placing undue stress on the system. 16x9 is also the same surface as 12x12 that works extremely well in the above mentioned 23/24' Yamaha boats.
Importantly, 16" is also the largest span to fit exactly flush with the transom (in my 2016 240).

TABS PLACEMENT
On boats powered by outboards or sterndrives it is necessary the trim tabs not be placed too close to the drive unit to avoid disturbing the water flow to the propeller thus causing ventilation. This is usually no closer than 7”. General rule is no less than 8" from the center of the drive. 16x9 tabs would fulfill those criteria, however that is probably an overkill anyway as the intakes in our jetboats are far removed and would not be obstructed with tabs. I have learned however to be conservative with any such estimates. That said, looking at the picture from @Williamsone46 (in an above post) - the tabs would be out of the water and out of the way of intakes FOR SURE at planning speeds. So, 16x9 tabs would work well here.

SHORT vs STANDARD ACTUATOR STROKE vs RANGE OF MOTION
This has been the trickiest item to tackle and plan around. Standard actuator has a stroke of 2.25" (fully extended) and affords approximately 16.6 degrees of tab movement, I think (see below). To determine how a switch to the short actuator (with a 1.5" stroke) affects the range, we did a little back-of-the-envelope calculation here (where a is the measurement between the hinge/transom and the actuator attachment point in the tab):

(this was drafted by my son, as we were driving and talking, he just whipped this up on his tablet)


Basically (some oversimplifications notwithstanding, such as ignoring the change in the actuator angle of attack - which should be fine as it only moves a total of <20% of its length, etc.):

The current standard actuator attached at 7.75" affords the range of motion of approximately 16.6 deg.
This would be mostly retained by using short actuator attached at 6" from the hinge/hull.


That is the final "best case" scenario we could came up with:

1. 16"x9" tabs
2. short 10" actuators with 1.5" stroke
3. 6" attachment point (in the center of the tab's span)


Additional considerations are a few. Taper would be initially bend up, but possible "drop fin" add-ons (AKA "DF12" in Bennett parts) would be considered, etc, all pending test results in the water. Chine overlap is not an issue with this design (I believe). Internal hull fiberglass enforcements of actuator attachments are strait forward, not discussed here.
Here is a rough sketch of tabs' placement:

(Short actuators' attachment points in the hull would not interfere w/ Wake Wedge mounting points / tie down eyes, and tabs would not interfere with fins)


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[OperationROL]

Love the approach. Following closely.

 

[Mainah]

I believe that hydraulic actuators are slimmer in diameter and using those may allow the tab to be retracted more or larger dimensions for the tab. Just throwing that out there since we are so space restrained at the transom.

 

[swatski]

I believe that hydraulic actuators are slimmer in diameter and using those may allow the tab to be retracted more or larger dimensions for the tab. Just throwing that out there since we are so space restrained at the transom.

That is true, and there are many advantages to hydraulic tabs, no motor and gear inside the tab and all. With Bennett, their "Premier" line is even slimmer. However, the set up here will accommodate an electric actuator thickness as long as it is short (10"), so at least that should not be a limiting factor.

Not to turn this into hydraulic vs electric discussion, the appeal of electric actuators for the "wake plate" application is that those may provide more precise position, velocity and speed control at extreme positions.

Load ratings should not be an issue here, all actuators considered have at least 1,000 lbs capacity (more than enough). If two actuators per tab were required I would go hydraulic, but the Lectrotab actuators rated at 1,000lbs are (theoretically) sufficient for up to 42-48" tab span (w/9" chord) by some accounts - so we should be safe here with 16" span.

Unless I'm missing something big, I think I'm ready to get the ball rolling. There are several other possible issues, but need tabs in hand at this point.

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[Glen]

@swatski
You thinking that knocking down the surf-side jet (Wedge or other) will still be necessary?

 

[swatski]

You thinking that knocking down the surf-side jet (Wedge or other) will still be necessary?

I think it would help. The Wedge is designed very well for that, and it seems to provide a bit of a delayed convergence action on top.
Courtesy of @jcyamaharider:


But then... There is @bobbie (NO Wedge)




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[swatski]

@swatski
You thinking that knocking down the surf-side jet (Wedge or other) will still be necessary?

I really think that, for surfing, the tabs need to retract way more than standard trim tab angle. If you look at the newest surf-edition rig, Cobalt R3, the surfing tabs are ENORMOUS and do not seem to go down much, but retract way higher than traditional. That is the OPPOSITE range bias of what traditional tabs do.



Not the best pics but here is a better shot:
https://jetboaters.net/threads/check-out-these-surfing-tabs.12095/

 

[swatski]

So, with Dan/Lectrolab assent today I've placed the order for tabs/actuators. Those are spec-ed basically as in post #31, above. I will provide more details as we go. This is a custom build so will take couple weeks.

Thank you @Bruce for blazing this trail, the guys are super easy to work with.

Regarding controllers, I'm trying to decide between SETR-61 and MLC-1. Leaning towards the latter, but not sure which one works better when moving a single tab up or down INDEPENDENTLY. I think I will go with whatever Dan/Lectrotab suggests, but please chime in if you are familiar with those, any input would be appreciated.
http://www.lectrotab.com/products/controls.php


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[2nazt]

I would go with SETR-61 for the auto retract alone. I plan to change my Module on my boat for a display and auto retract. But I would mess one up on my boat if I trailer with them engaged.

Is there more adjustments on one compared to the other?

 

[swatski]

I would go with SETR-61 for the auto retract alone. I plan to change my Module on my boat for a display and auto retract. But I would mess one up on my boat if I trailer with them engaged.

Is there more adjustments on one compared to the other?

Both models (SETR-61 and MLC-1) have auto-retract, that is a must-have.
Regarding controllers, I like the MLC-1 better I think. But it is newer w/not a whole lot info out there, and I have some questions:
Q: To move a tab up and down -- how is it done with a single button in MLC-1?
Does the tab move all the way before reversing directions?
Do the (side) buttons in MLC-1 toggle?
Does a side tab move both tabs simultaneously (one up, the other one down)?

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